Narrated Abu Hurairah (RA):

Allah's Messenger (ﷺ) said: "The most excellent prayer after that which is obligatory is the (voluntary) late night prayer." [Reported by Muslim].

وَعَنْ أَبِي هُرَيْرَةَ ‏- رضى الله عنه ‏- قَالَ : قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{ أَفْضَلُ اَلصَّلَاةِ بَعْدَ اَلْفَرِيضَةِ صَلَاةُ اَللَّيْلِ } أَخْرَجَهُ مُسْلِمٌ .‏ [1]‏